Pellable seal package

Abstract

An improved heat sealable, peelable seal package structure having walls defined by sheet members and having a region where a first wall portion overlaps upon a second wall portion. The overlapping portions are heat sealable together but are thereafter separatable by peeling. The surface of such first wall portion is comprised of an ethylene acid copolymer, preferably of the ionomer type, and the surface of such second wall portion is comprised of a polyblend of polyethylene and ethylene vinyl acetate copolymer.

I claim: 
     
       1. A heat sealable, peelable seal package having walls defined by sheet members and having at least one region where a first wall portion overlies a second wall portion in adjacent relationship, said overlying portions being heat sealable together and thereafter being separatable by peeling, the surface of said first wall portion so adjacent said second wall portion being comprised of an ethylene acid copolymer, and the surface of said second wall portion so adjacent said first wall portion being comprised of a polyblend of polyethylene and ethylene vinyl acetate copolymer, said polyblend being comprised on a 100 weight percent basis of from about 99 to 67 weight percent of said polyethylene, and, correspondingly, from about 1 to 33 weight percent of said ethylene vinyl acetate copolymer. 
     
     
       2. The package of claim 1 wherein said first wall portion and said second wall portion are each a laminated sheet member comprised of at least two layers. 
     
     
       3. The package of claim 1 wherein said ethylene acid copolymer comprises ethlene/(meth)acrylic acid. 
     
     
       4. The package of claim 3 wherein said ethylene/(meth)acrylic acid copolymer is in the form of a salt selected from the group consisting of sodium and zinc. 
     
     
       5. The package of claim 1 wherein: (A) said first wall portion consists of a generally dish-shaped relatively rigid formed product receiving member having a central product receiving cavity and a generally outwardly flanged perimeter and wherein the inside surface portions thereof are comprised of a layer of said ethylene acid copolymer, and   (B) said second wall portion consists of a generally relatively flexible covering film member having edge portions configured to overlie said flanged perimeter and wherein the inside surface portions thereof are comprised of a layer of said polyblend.   
     
     
       6. The package of claim 1 wherein: (A) said first wall portion consists of said ethylene acid copolymer, and   (B) said second wall portion consists of said polyblend.   
     
     
       7. The package of claim 1 wherein said each of said first and said second wall portions consist of a laminate film structure characterized by having one surface thereof comprised of a layer of said ethylene acid copolymer, and by having the opposed surface thereof comprised of a layer of said polyblend of polyethylene and ethylene vinyl acetate copolymer. 
     
     
       8. A laminate sheet structure for the manufacture of a container having a peelable seal wherein one surface thereof is formed by a layer of ethylene acid copolymer and wherein the opposed surface thereof is formed by a layer of a polyblend of polyethylene and ethylene vinyl acetate copolymer. 
     
     
       9. An improved peelable seal package comprising: a generally dish-shaped relatively rigid, formed product receiving member having defined therein a central product receiving cavity and a generally outwardly extending flanged perimeter;   a generally relatively flexible covering film member having edge portions configured to overlie said flanged perimeters;   said product receiving member comprising a first multilayered interfacially bonded laminate wherein: the outer layer thereof is comprised of a polyamide which has sufficient thickness to be thermoformable into a said relatively rigid dish-shaped configuration,   an intermediate layer thereof is comprised of a polyester adhesive, and   the inner layer thereof is comprised of a surlyn ionomer;     said covering film member comprising a second multilayered interfacially bonded laminate wherein: the outer layer thereof is comprised of a polymers selected from the class consisting of polyamides and polyesters and has generally insufficient thickness to be thermoformable,   an intermediate layer thereof is comprised of a polyester adhesive, and   the inner layer thereof is comprised of a polyblend of ethylene vinyl acetate and polyethylene;     said flanged perimeter being heat bondable to said edge portions, the resulting bond being characterizied by a capacity to be separated by peeling.   
     
     
       10. The package of claim 9 wherein a layer of a saran polymer is interposed between said outer layer and said polyester adhesive in each of said product receiving member and said covering film member.